BEIJING - When it comes to climbing China's bureaucratic ladder, closing factories to cut greenhouse gas emissions can be a career booster.

Huang Huikang, as vice mayor of Tangshan in northeastern China, made energy efficiency one of his top priorities, taking aggressive steps to curb greenhouse gases from the city's many factories. Today he is China's special representative on climate change, negotiating with officials from countries worldwide.

As Huang explains it, he and his colleagues managed - at least in one city - to meet the challenge of reducing emissions while still promoting rapid economic growth.

They did not simply shutter factories in Tangshan, a major steel- and cement-producing center, but replaced them with cleaner-burning plants. Of course making these changes by government fiat is easier in a country where officials do not face democratic elections.

"We shut down 1,500 highly-polluting factories," Huang said, adding that even as he did so the city's gross domestic product doubled twice in the past five years, to $400 million.

In the United States, many politicians are reluctant to impose mandatory curbs on heat-trapping gases, fearing a political backlash. But the Chinese government has begun to make some inroads into its greenhouse gas emissions by holding accountable local and provincial officials - as well as the nation's top 1,000 emitters.

In some cases the Chinese government is relying on stopgap measures to meet this year's target to improve energy efficiency per unit of economic activity.

In the campaign that began in August, several provincial governments have ordered steel mills to work nine days straight and then take five days off and cut off cement plants' electricity supplies for periods of time, threatening to publicly expose factories that defy the new rules.

But the lack of a national accounting standard for emissions makes it difficult for independent observers in China and elsewhere to monitor how much progress is being made.

Ranping Song, WRI's program manager working on greenhouse gas accounting, said his group and others are working on how to bring China into compliance with international standards, but it remains unclear whether companies will disclose their data publicly, and how they'll be held accountable if they miss targets.

"It may be difficult for the government to get the right information to make the right decisions," he said.

Without a transparent and comparable system of lowering global warming emissions, Center for Clean Air Policy president Ned Helme warned, "there's always the risk that some people don't do it" and the world falls short of "where we need to be as a global commons."

The challenges facing China were visible during a recent visit to the headquarters of Sinopec Shanghai Petrochemical, one of China's top producers of chemicals, plastics and refined oil. Officials there said they were reducing their relative carbon output but could not supply those statistics and the government - not the company - tracks such data. And between 2009 and 2010 Sinopec Shanghai increased its annual oil refinery production from 8.7 million to 10.7 million tons, a number that is expected to grow in the coming years.

"It is a paradox, actually, in terms of the technological process of production. In a sense you need to produce more carbon dioxide," said Gao Jinping, chairman of the company's supervisor committee. But he added that the company has become more efficient and has prioritized environmental considerations. "We are certain we can meet the demand from the government to lower our emissions."

Still, there are downsides to China's "go it alone" approach. Zou Ji, the country's director for the World Resources Institute, said the nation's rapid growth over the past five years may mean it fails to meet its energy intensity target. As Chinese become wealthier, buy cars and move to the city at a rate of 24 million a year, all of this contributes to higher carbon emissions.

"One of the implications is it will be tougher to meet more ambitious targets in the future," Zou said, adding that when it comes to near-term emission cuts, "there will be some improvement compared to the baseline as business as usual. I would not be very optimistic in absolute terms."

But with U.S. climate legislation and international negotiations stymied, activists and scientists who warn the world is failing to cut carbon pollution fast enough point to China's efforts.

"The crux of the debate is, China is doing something," said Alex Wang, director of the Beijing-based China Environmental Law Project at the Natural Resources Defense Council. "Neither the U.S. nor China is doing enough to address the risks of climate change. But we're seeing a lot of reason for frustration in the U.S. In China, from the policy perspective, there's a tremendous amount going on."

While the Chinese government will come close to meeting its target, it's unclear if it willl reach it entirely. It has set a more ambitious target for the next decade, pledging to cut its carbon output per unit of economic activity between 40 and 45 percent by 2020.

These commitments are modest compared to ones by industrialized nations such as Japan and members of the European Union. But they are significant given that China has no international obligation to slow its rate of emissions growth, and far beyond what countries such as India have pledged to do.

Nationwide, between 2006 and 2009 China replaced 7 percent of its electricity generation capacity with cleaner power plants, according to the Joint U.S.-China Collaboration on Clean Energy.

In the past several months, Chinese officials have intensified their focus, announcing they will replace outdated equipment in 2,000 power plants and spend $75 billion a year on clean energy technology, a figure triple the size of the Energy Department's entire budget. And they are quietly being trained by American and European experts on how to trade emissions credits within a given industry to cut greenhouse gases.

"You really see a greater emphasis on these kinds of things, especially within the industrial sector," said Ned Helme, president of the D.C.-based Center for Clean Air Policy.

Angela Anderson, program director for the U.S. Climate Action Network, said American and Chinese politicians will cut emissions only if they see it as promoting long-term economic and energy security. "What's different is China does see it as in its best interest, while the U.S. is still debating it."